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The US Centers for Disease Control and Prevention (CDC) has found that some coronavirus test kits delivered to state laboratories are faulty.

The test kits were delivered to enable states to carry out testing locally rather than transporting samples to CDC headquarters in Atlanta, expediting the diagnosis process.

The public health institute is working to ship replacements, report Reuters.

After receiving the test kits, state labs must verify them to ensure that they function correctly.

However, some public health labs reported that during a routine verification process, the kits provided inconclusive results.

In a press conference, CDC National Center for Immunization and Respiratory Diseases director Dr Nancy Messonnier said: “When a state gets the test kits, they have to verify that it works the same in their lab that it worked at CDC.

“And when some states were doing this, we received feedback that they weren’t, that it wasn’t working as expected, specifically some public health labs at states were getting inconclusive results and what that means is that test results were not coming back as false positive or false negatives but they were being read as inconclusive.”

Messonnier speculates that an issue with one of three assays and inconsistent performance by a reagent are likely behind the inconclusive results.

However, officials did not specify how many kits were faulty.

Meanwhile, the death toll due to coronavirus outbreak jumped to 1,369 with 254 new fatalities reported at the end of 12 February.

Recently, the virus was officially named Covid-19 by the World Health Organization (WHO).

The total number of Covid-19 cases in the US is 14.